Damage And Controlling Techniques Of Eriosoma Lanigerum In YanTai Area

Eriosoma lanigerum is an important quarantine object harming Malus fruit trees. In this research, techniques for controlling the pests in Shandong province, especially in Jiaodong peninsula were studied in the period of 6 months every year, from May to October, when Eriosoma lanigerum Hausann flourish. The study was carried out in Haiyang, Qixia, Laiyang, Mouping and Zhaoyuan, which are five counties in Shandong province. Three to five selected orchards in each county were investigated by means of site-investigation, and the results were analyzed combined with general investigation. The study suggests that:1. The host plants include various kinds of fruit trees of Malus and haw trees;The harm mainly happens in the orchards which has a poor management and a severely Appletree canker disease;Temperature is the main influencing weather factor of harm degree;Natural diffuse is the main way of spreading in corresponding area;Primary natural enemy is Aphelinus Mali Hald, which can not control the harm effectively.2. The density of group has a negative correlation with the yield and a positive correlation with the rate of loss. The losses of yield of Xiaoguoguang and Hongfushi, two cultivars of apple, are 0.00449kg and 0.00208kg when there increases one unit group of Eriosoma lanigerum Hausann on the apple; and correspondingly, the rates of loss yield add 0.00291% and 0.00204% respectively. The mathematic model of economic threshold is:3. The key techniques of controlling on the harm include: strengthen the plant quarantine monitoring; enhance garden management; choose the pesticides which are highly effective, low poisonous and with little remnant, like Avermectin, and use them in scientifically and befittingly; pay attention to the protection of natural enemy and the compound or single control technique and measure should be employed based on the factual conditions of the garden or the fruit trees.